A gas turbine engine generally includes, in serial flow order, a compressor section, a combustion section, a turbine section and an exhaust section. In operation, air enters an inlet of the compressor section where one or more axial compressors progressively compress the air until it reaches the combustion section. Fuel is mixed with the compressed air and burned within the combustion section to provide combustion gases. The combustion gases are routed from the combustion section through a hot gas path defined within the turbine section and then exhausted from the turbine section via the exhaust section.
In particular configurations, the turbine section includes, in serial flow order, a high pressure (HP) turbine and a low pressure (LP) turbine. The HP turbine and the LP turbine each include various rotatable turbine components such as turbine rotor blades, rotor disks and retainers, and various stationary turbine components such as stator vanes or nozzles, turbine shrouds and engine frames. The rotatable and the stationary turbine components at least partially define the hot gas path through the turbine section. As the combustion gases flow through the hot gas path, thermal energy is transferred from the combustion gases to the rotatable turbine components and the stationary turbine components.
Nozzles utilized in gas turbine engines, and in particular HP turbine nozzles, are often arranged as an array of airfoil-shaped vanes extending between annular inner and outer bands which define the primary flowpath through the nozzles. Further, the spacing between and orientation of the components of neighboring nozzles arranged in an annular array is of particular concern for optimal gas turbine engine performance. Various engineering dimensions between features of neighboring nozzles, and in particular the airfoils thereof, are measured and evaluated. It is generally desirable that these engineering dimensions are within desired predetermined tolerances for optimal gas turbine engine performance. One engineering dimension that is of particular concern is the dimension between a trailing edge of an airfoil of a nozzle and a high camber location on a suction side of an airfoil of a neighboring nozzle. This engineering dimension is sometimes termed the “A41” dimension. If this dimension is smaller than a predetermined optimal range of dimensions, the gas turbine engine compressor can stall. If this dimension is larger than the predetermined optimal range of dimensions, the efficiency of the gas turbine engine can be lowered.
Accordingly, improved methods for positioning neighboring nozzles are desired. In particular, methods which provide for positioning such that particular engineering dimensions between the neighboring nozzles are within predetermined tolerances would be advantageous.